The present invention relates to a surface plasmon resonance (SPR) detecting apparatus and a method thereof, and more particularly, to an SPR detecting apparatus using an electrode induction electrowetting method.
At present, fluids required by biochemical detection chips are all continuous fluid, and most common driving technology of biochemical detection chips use a pressure difference and a tubing pump to provide a necessary driving force. However, due to the requirements of miniaturization and precision on the detection technology, the usage of continuous fluid will suffer the following problems. For example, a cross-infection between detection chip and a sample, a block in a pipeline of a micro-channel, and residual in the channel will influence the result of next detection. Moreover, if a continuous fluid is used, a great amount of sample is demanded as a sample solution must fill up the whole channel from a driving force source to the detection chip. Therefore, the biochemical detection chip is hard to be applicable for a small amount of sample and will waste a lot of valuable samples. In addition, the pump for driving the continuous fluid has a large volume and is hard to be integrated into a system.
At present, a fluid in a common biochemical detection system is usually conveyed in a continuous manner. For example, a driving device (such as a pump) is used to push liquid to continuously flow into a fluid passageway (such as a pipeline and a channel). If the width of the channel is 1 cm or more, a mechanical precision processing method may be adopted to manufacture the channel; and if the width of the channel is smaller than 1 cm, a simple micro-channel manufacturing technology is adopted to manufacture the channel. For example, with regard to a fluid transfer system manufactured by an SPR manufacturer Biacore Company, in U.S. Pat. No. 6,008,893, a fluid is driven by a tubing pump to flow into a testing area through a pipeline, and a reaction signal is detected by an optical system in the testing area. In another U.S. Pat. No. 6,698,454 of Biacore Company, a mechanical precision processing method is adopted to manufacture a channel, and a fluid under test is driven by an external pump. In U.S. Pat. No. 7,193,703 of Fuji Photo Film Co., Ltd., the mechanically processed channel of an SPR detecting apparatus penetrates into a prismatic structure, and after a liquid under test flows into the channel, a light is irradiated on a detection area to perform the detection.
The aforementioned patents are all developed to control the continuous fluid. However, the innovative idea of controlling discrete droplets may in a more advanced manner. In aspect of technology, some documents about an electrowetting method for controlling a fluid have been published in recent years, but such a method have not been applied in an apparatus integrated with a biochemical detection system.